Revert "drm/i915: Make intel_display_suspend atomic, v2."

Revert "drm/i915: Make intel_display_suspend atomic, v2."

This reverts commit 490f400db5d886fc28566af69b02f6497f31be4b.

We're not ready yet to make it atomic, we calculate some state in
advance, but without atomic plane support atomic the hw readout will
fail.

It's required to revert this commit to revert the atomic hw
state readout patch.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90868
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90861
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>